Helmet



FIG. 1 is a front perspective view of a helmet showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is an enlarged view of the portion indicated by crop lines 3-3 in FIG. 1 thereof;

FIG. 4 is an enlarged view of the portion indicated by crop lines 4-4 in FIG. 2 thereof;

FIG. 5 is a partial enlarged cross-sectional view taken along line 5-5 in FIG. 2 thereof; and,

FIG. 6 is an enlarged cross-sectional view taken along line 6-6 in FIG. 5 thereof.

The broken lines illustrate portions of the helmet and form no part of the claimed design. The dash-dotted lines denote the boundary of the claim and form no part of the claimed design. 

CLAIM The ornamental design for a helmet, as shown and described. 